[en] We and other groups have reported the selective introduction of nucleophiles at the secondary benzylic position of the Baylis-Hillman acetates via the corresponding DABCO salts. Thus, we envisioned that we could prepare 4-methylene- 2-cyclohexenone skeleton and para-methoxymethyl anisoles by combining the DABCO salt concept and the aromatization reaction with iodine in methanol. Suitably substituted anisoles are useful as the starting materials for the fragrances, dyes and pesticides, as antioxidants in oils and fats, or as stabilizers of plastics. Moreover, paramethoxymethyl anisoles have been used for the kinetic acetalization of diol or amino alcohol systems in the presence of DDQ5 during the synthesis of (+)-FR900482, taxotere side chain,5c cyclopropyl lactone oxylipins, and erythromycin A.

[en] Highlights: • H^E for binary systems of cycloalkanones with n-nonane have been measured. • Experimental data were well represented by the Redlich–Kister equation. • The experimental results have been used to test the applicability of the Wilson, NRTL and UNIQUAC models. - Abstract: Excess molar enthalpies, H^E, for the binary mixtures of cyclopentanone, cyclohexanone, or cycloheptanone with n-nonane were measured at T = 298.15 K and 0.1 MPa, by means of a Setaram Tian-Calvet MS80 microcalorimeter. All the binary systems investigated show endothermic behaviour (positive values) over the whole mole fraction range. The molar excess enthalpies decrease as the size of the cycloalkanone increases. The experimental results of H^E are fitted to the Redlich–Kister equation to correlate the composition dependence. The experimental H^E data are also used to test the suitability of the Wilson, NRTL, and UNIQUAC models. The correlation of excess enthalpy data in these binary systems using the UNIQUAC model provides relatively the most appropriate results

[en] Highlights: • First report for photoisomerization of cyclohexanone to butylketene in vapor phase. • Rotational contour of ν_C=O band of butylketene is simulated for its identification. • Verified experimentally that butylketene is a primary photoproduct. • In the proposed photolysis mechanism, diradical formation may occur in S₀ state. Photoisomerization channels in the vapor phase photochemistry of cyclohexanone (CH) are studied by performing photolysis with 311 nm UV light, and analyzing the photoproducts by means of FTIR spectroscopy. In addition to 5-hexenal, identified previously as a photoisomerization product, we observe an efficient parallel isomerization channel producing butylketene as a primary photoproduct, but it remained unidentified in earlier studies. Calculation at DFT/B3LYP/6-311++G^∗∗ level predicts formation of this ketene to be favorable both with respect to thermodynamic and kinetic factors.

No abstract available

[en] An efficient method for the preparation of 8-benzylidene-4-phenyl-3,4,5,6,7,8-hexahydro-1H-quinazolin-2-ones/thiones from the reaction of aromatic aldehydes with cyclohexanone and urea or thiourea in the presence of Tetrabutylammonium hexatungstate, [TBA]₂[W₆O₁₉], as an efficient, inexpensive catalyst under thermal and solvent-free conditions has been developed. Good yields, short reaction times, straightforward workup, reusability of the catalyst, and green conditions are the most obvious advantages of this procedure

No abstract available

[en] The paper contains the results of determining the physical and chemical characteristics of lead sorption by impregnated sorbents based on Di-(tert-butylcyclohexano)-18-crown-6 and different diluents (1,1,7-trihydrododecafluoroheptanol, ionic liquid). The results of studying the influence of sorption time (kinetics) and lead concentration in the initial solution (isotherm) on the degree of lead extraction by the obtained sorbents, as well as the selectivity of lead sorption against other metals, were presented for the first time. These characteristics are important to justify the ratio of the solution to the sorbent for concentration and separation from related impurities, the rate of transmission of the solution through the sorbent, estimates of the amount of stable tracer to be inserted. The specific activity of ²¹⁰Pb in the Black Sea was determined for the first time using the obtained sorbents. Samples for determining the specific activity of ²¹⁰Pb in sea water were taken on cruise 101 of the R/V 'Professor Vodyanitsky' (December 14-28, 2017). (author)

[en] Polymethine and ESIPT dyes are known to act as fascinating compounds for several applications. However, a combination of both fluorophores as a single molecule is poorly investigated. In this work, we report for the first time the successful synthesis of streptocyanine-ESIPT derivatives through a simple three-step route. Our synthetic route involves the coupling between amino ESIPT dyes and an iminium salt formed through the reaction between Vilsmeier-Haack reagent and cyclohexanone. Remarkably, the presence of a polymethine chain between two ESIPT nuclei changed the photophysical properties of the fluorophores individually. The new streptocyanine-ESIPT dyes contains electron acceptors groups able to increase of the conjugation of the π-system. In addition, the outstanding combination of these two different class of dye molecules increased significantly the Stokes shift of polymethine dyes, which enable the future application of these derivatives as efficient biological probes.

[en] The addition of lithium enolates and TMS ethers of cyclohexanone and cyclododecanone to levoglucosenone in the presence of Lewis acids was studied. It was established that the optimal way to obtain of Michael adducts involves the reaction levoglucosenone at −78°C with lithium enolates of cyclohexanone and cyclododecanone in the presence of ZnCl₂. Additional amounts of Michael adducts can be obtained by treatment of 1,2-adducts with lithium diisopropylamine. 1,2-Adducts are best prepared by the reaction of the corresponding lithium enolates with levoglucosenone in the presence of Ti(Oi-Pr)₄.

No abstract available